This has been requested by lots of bandsmen who have been used with ebonite or metal flutes and never had to oil them. This informational video shows how to clean, strip and oil the flute. Wooden flutes need to be oiled about once a month once they are blown in and should be cleaned after every parade or lengthy rehearsal session.
Once your flute is cleaned, store it away in a box or pvc pipe, don't leave it on a windowsill, never leave it on the back seat of the car and make sure it isn't left anywhere too warm.
When assembling the headjoint, make sure you twist them together gently,if it feels too tight, don't force it, let them both come to temperature in the room for about 10 mins and try again, use cork grease if you have it.
You don't have to remove the keys every time you clean your flute thoroughly, you can cover the pads with tin foil so that the oil doesn't get onto them, but remember only to coat the inside bore with a fine layer of oil when doing it this way, and always remove all of the oil after 24 hrs.
if you are unfortunate enough to break your flute, most of the makers and suppliers will repair them and they will all do a good job. Email me at firstname.lastname@example.org if you want further advice or contacts.